反应详情

A suspension of 100 mg (0.38 mmol) of methyl 5-(acetoxymethyl)-4,7-dihydro-7-oxo-s-triazolo[1,5-a]pyrimidine-2-carboxylate in 7 ml of phosphorus oxychloride is held under reflux for 6 hours and subsequently concentrated in a vacuum. The residue is dissolved in dichloromethane. The solution is washed with ice/water, dried over sodium sulphate and concentrated. After crystallization from methanol/diethyl ether there are obtained 70 mg of methyl 5-(acetoxymethyl)-7-chloro-s-triazolo[1,5-a]pyrimidine-2-carboxylate as brown crystals of melting point 120° C.

1. temperatureunder reflux for 6 hours
2. concentrationsubsequently concentrated in a vacuum
3. dissolutionThe residue is dissolved in dichloromethane
4. washThe solution is washed with ice/water
5. dry with materialdried over sodium sulphate
6. concentrationconcentrated
7. customAfter crystallization from methanol/diethyl ether there